The present invention belongs to the field of mixers for mixing materials such as food and chemicals, and in particular, relates to a partitioning device which protects hands of operators by preventing such hands from entering into the bowl in which a material is being mixed and prevents the material from scattering.
The present inventor proposed a partitioning device for mixer of this kind, which was disclosed in Japanese patent unexamined publication gazette 2001-38186. The partitioning device is designed for a mixer wherein a bowl is supported on the front side of a pillar of the machine body, and a mixing tool is rotated in the bowl by a mixing shaft which extends downward from a head protruding forward from the upper part of the pillar. The partitioning device comprises an annular guide ring which is arranged to surround the mixing shaft beneath the head, a protective fence which is formed into a tube having a local opening and extends from the guide ring toward the circumference of the bowl, and a guide rail which is mounted on the machine body to surround the outer circumference of the guide ring and rotatably support rollers being fitted with the guide ring. When the protective fence is located to cover the upper part of the front of the bowl, hands of operators will be prevented from entering into the rotation area of the mixing tool. When the protective fence is moved revolutionarily so that its opening comes to the upper part of the front of the bowl, the operators will be able to feed materials, visually check the materials in the bowl, and fix or unfix the mixing tool. The guide rail is divided into two parts, a right one and a left one, and they are disconnectably fitted together. With this division, the partitioning device can be put on or taken away from the machine body. With this arrangement, the protective fence can be washed whole, and the interior of the machine body can be cleaned easily, and in turn, the sanitary conditions of the mixer can be maintained satisfactorily.
To disconnectably fit the guide rail, which is divided into two parts, the right portion and the left portion, onto this mixer, the mixer is provided with fitting means such as buckles. When the protective fence is to be disconnected from the machine body, if the fitting means are undone, the protective fence will drop off the guide rail. Hence it is necessary to hold the protective fence by one hand and undo the fitting means by the other hand. This will exceedingly reduce the efficiency of the operation. To cope with this, one idea may be to provide the machine body with a leaf spring at a point which comes below the guide ring of the protective fence to receive the falling protective fence once by this leaf spring. Then the operator can pull the protective fence downwards by exerting a force which exceeds the elastic force of the leaf spring to retract and disconnect the protective fence from the machine body. In this way the operator can disconnect the protective fence from the machine body by holding the protective fence with both hands. In this case, however, when the protective fence is to be installed on the machine body, the operator will need to flex the leaf spring in the reverse direction. This, in turn, will require a knack in fitting the protective fence on the machine body and pose a problem of reduced efficiency of operation.
As mixers are produced according to varied sets of specifications and protective fences which are applicable to these mixers vary in size, varied guide rails must be provided according to the kinds of the protective fences. This is a cost-raising factor.
If the guide ring of the protective fence is not formed to be a true circle due to, for example, dispersion in manufacture, the gap between the guide ring and the roller is not constant along the circumference and will pose a problem of irregular revolutionary movement of the protective fence and, in turn, difficulty in its use.
The present invention was made in view of these points, and its objective is to provide a partitioning device for mixer, wherein a partitioning member such as a protective fence is held by movable rollers, and with this arrangement, the partitioning member can be removed from or installed on the machine body of the mixer by holding the partitioning member by both hands, and a plurality of kinds of partitioning members can be used commonly, and dispersions in the configuration of individual partitioning members are absorbed to ensure their smooth revolutionary movement.
To accomplish the above-mentioned objective, the partitioning device for mixer according to the present invention is a partitioning device which is provided on a mixer wherein a bowl is held on the front side of the pillar of the machine body, and a mixing tool is rotated in the bowl by a mixing shaft which extends downward from a head protruding forward from the upper part of the pillar, the partitioning device is characterized in that it comprises a partitioning member, which has an annular rail being arranged beneath the head to surround the mixing shaft and a surface member having a local opening and being formed into a tube to extend from the rail toward the circumference of the bowl, a total of at least three rollers being a combination of fixed roller and movable roller, which fit with the rail of the partitioning member from the inside or the outside to support the partitioning member movably around the mixing shaft, a fixed roller supporting means, which rotatably supports the fixed roller in such a way that the fixed roller is prevented from shifting in relation to the machine body, and a movable roller supporting means, which supports the movable roller in such a way that the movable roller can rotate and the distance between the movable roller and the fixed roller can be varied, and energizes the movable roller in a direction to close to the fixed roller.
In the case of this partitioning device for mixer, the partitioning member is made to move by rotating the fixed roller and the movable roller which fit with the rail thereof. When the partitioning member is positioned to cover the upper part of the front of the bowl, hands of the operator will be prevented from entering into the rotation area of the mixing tool, and the materials will be prevented from being scattered. Moreover, when the partitioning member is positioned in such a way that its opening comes to the upper part of the front of the bowl, the operator will be able to feed a material, visually check the material in the bowl and fix or unfix a mixing tool.
When the partitioning member is to be removed from the machine body, the operator will hold the partitioning member by hands and push the partitioning member to press the movable roller in a direction against its energizing force. Then the rail of the partitioning member will come off the fixed roller. When the operator lowers the released rail portion to shift the partitioning member downward aslant away from the fixed roller, the partitioning member will be removed from the machine body. When the partitioning member is to be fitted on the machine body, the operator will hold the partitioning member by hands in such a way that the movable roller side of the partitioning member is raised a little higher than the other side, and the operator will fit the rail of the partitioning member with the movable roller and push the movable roller in a direction against its energizing force, then make the partitioning member level and allow the partitioning member to move in the direction of the energizing force of the movable roller so that the rail of the partitioning member fits with the fixed roller. As a result, the partitioning member will be fitted on the machine. The above-mentioned operation can be done easily by holding the partitioning member with both hands. When the partitioning member is removed from the machine body, the partitioning member can be washed whole, and the interior of the machine body can be cleaned with ease, and the sanitary conditions of the mixer can be maintained satisfactorily.
As the movable roller is held in such a way that the distance between the movable roller and the fixed roller can be varied, and is energized in a direction to close to the fixed roller, a plurality of partitioning members of varied rail diameters can be supported between the fixed roller and the movable roller, and the cost can be reduced through the use of common parts for various mixers. Moreover, even if the rail of a partitioning member is out of a true circle, the movable roller will shift to vary the distance between the movable roller and the fixed roller. Hence the fixed roller and the movable roller can fit with the rail stably and the partitioning member can make smooth revolutionary movement.
As described above, the partitioning device for mixer according to the present invention can ensure the safety of the operators, prevent the materials from scattering, and provide convenience of feeding materials or the like, by means of the partitioning member, and can maintain the sanitary conditions of the mixer satisfactorily by allowing the partitioning member to be fitted on or removed from the machine body. Moreover, as the partitioning member can be removed from or fitted on the machine body by holding it with both hands, the efficiency of fitting or removing the partitioning member can be enhanced significantly. Furthermore, as a plurality of different kinds of partitioning members can be used in common, the cost can be reduced. As the dispersion or tolerance in the configuration of rails of partitioning members can be compensated or absorbed, smooth revolutionary movement of the partitioning members can be assured.